The present disclosure provides a method for calibrating brightness unevenness of an OLED display panel, the method includes: getting a brightness matrix of an OLED display panel in at least three gray scales, and determining a uniform brightness area and an uneven brightness area, and calculating a fitting Gamma value of each pixel corresponding to the at least three gray scales in the uneven brightness area, and fitting the fitting Gamma curve of the each pixel in the uneven brightness area, and calibrating the brightness of the uneven brightness area based on the fitting Gamma curve of the each pixel. The present disclosure can improve the accurate of the calibrating brightness and the efficiency of the calibration.